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Cheap flights from Portland, Maine to London from $439

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Portland, Maine to London departing on 10/28. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
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0 bags

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Find the cheapest flights from Portland, Maine to London

Cheap round-trip flights

Enter your travel dates to find the best prices.
United Airlines Logo
5:25 am - 8:20 amPWM-LHR
21h 55m2 stops
United Airlines Logo
9:10 am - 11:17 pmLHR-PWM
19h 07m1 stop
$687United Airlines
Find Deal
Sun, Nov 2 - Sat, Nov 8
JetBlue Logo
2:17 pm - 9:30 amPWM-LHR
14h 13m1 stop
JetBlue Logo
8:15 am - 11:04 pmLHR-PWM
19h 49m1 stop
$700JetBlue
Find Deal
Wed, Oct 15 - Wed, Oct 22
KLM Logo
4:53 pm - 8:45 amPWM-LHR
10h 52m1 stop
KLM Logo
11:45 am - 11:54 pmLHR-PWM
17h 09m2 stops
$721KLM
Find Deal
Tue, Nov 18 - Tue, Nov 25
Delta Logo
6:00 am - 6:55 amPWM-LHR
19h 55m1 stop
Delta Logo
10:00 am - 11:21 pmLHR-PWM
18h 21m2 stops
$722Delta
Find Deal
Mon, Dec 1 - Tue, Dec 9
Delta Logo
4:43 pm - 11:25 amPWM-LHR
13h 42m2 stops
Delta Logo
10:00 am - 11:21 pmLHR-PWM
18h 21m2 stops
$726Delta
Find Deal
Wed, Dec 3 - Wed, Dec 10
Scandinavian Airlines Logo
2:30 pm - 4:00 pmPWM-LHR
20h 30m2 stops
Scandinavian Airlines Logo
6:40 pm - 11:54 pmLHR-PWM
34h 14m2 stops
$734Scandinavian Airlines
Find Deal
Fri, Nov 14 - Fri, Nov 21
KLM Logo
1:25 pm - 9:00 amPWM-LHR
14h 35m1 stop
KLM Logo
4:10 pm - 11:54 pmLHR-PWM
12h 44m1 stop
$749KLM
Find Deal
Tue, Nov 18 - Tue, Nov 25
American Airlines Logo
12:38 pm - 6:30 amPWM-LHR
12h 52m2 stops
American Airlines Logo
1:10 pm - 11:41 pmLHR-PWM
15h 31m2 stops
$753American Airlines
Find Deal
Tue, Nov 18 - Tue, Nov 25
American Airlines Logo
5:37 pm - 10:25 amPWM-LHR
11h 48m1 stop
American Airlines Logo
7:50 am - 6:10 pmLHR-PWM
15h 20m2 stops
$767American Airlines
Find Deal
Fri, Nov 14 - Fri, Nov 21
Scandinavian Airlines Logo
2:35 pm - 9:20 amPWM-LHR
14h 45m2 stops
Scandinavian Airlines Logo
6:40 am - 11:59 pmLHR-PWM
22h 19m2 stops
$836Scandinavian Airlines
Find Deal
Fri, Mar 20 - Mon, May 4

United Airlines flights from Portland, Maine to London Heathrow Airport

Our best United Airlines deals on Portland, Maine to London Heathrow Airport flight tickets
United Airlines
Nov 2
PWM5:25 amPortland
21h 55m
2 stops
LHR8:20 amLondon Heathrow
Nov 8
LHR9:10 amLondon Heathrow
19h 07m
1 stop
PWM11:17 pmPortland
$687
Find similar
United Airlines
Nov 2
PWM5:25 amPortland
23h 00m
1 stop
LHR9:25 amLondon Heathrow
Nov 8
LHR9:10 amLondon Heathrow
19h 07m
1 stop
PWM11:17 pmPortland
$966
Find similar
United Airlines
Oct 14
PWM2:34 pmPortland
11h 21m
1 stop
LHR6:55 amLondon Heathrow
Oct 18
LHR7:45 amLondon Heathrow
15h 53m
2 stops
PWM6:38 pmPortland
$1,720
Find similar

JetBlue flights from Portland, Maine to London Heathrow Airport

Our best JetBlue deals on Portland, Maine to London Heathrow Airport flight tickets
JetBlue
Oct 15
PWM2:17 pmPortland
14h 13m
1 stop
LHR9:30 amLondon Heathrow
Oct 22
LHR8:15 amLondon Heathrow
19h 49m
1 stop
PWM11:04 pmPortland
$700
Find similar
JetBlue
Oct 3
PWM2:17 pmPortland
25h 28m
1 stop
LHR8:45 pmLondon Heathrow
Oct 7
LHR8:15 amLondon Heathrow
19h 49m
1 stop
PWM11:04 pmPortland
$720
Find similar
JetBlue
Oct 5
PWM2:17 pmPortland
14h 13m
1 stop
LHR9:30 amLondon Heathrow
Oct 7
LHR11:55 amLondon Heathrow
16h 09m
1 stop
PWM11:04 pmPortland
$902
Find similar

momondo Fare Finder

 
Customize your flight search to find flights from Portland, Maine to London Heathrow Airport that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, momondo users made 832,500 searches. Data last updated October 2, 2025.
Use the filters below to find and compare flights from Portland, Maine to London Heathrow Airport that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

PortlandLondon

PWM - LHR

PWMLHR

Portland

Sun 11/2

5:25 am-8:20 am

2 stops21h 55m

London Heathrow

Sat 11/8

9:10 am-11:17 pm

1 stop19h 07m

$687

PortlandLondon

PWM - LHR

PWMLHR

Portland

Wed 10/15

2:17 pm-9:30 am

1 stop14h 13m

London Heathrow

Wed 10/22

8:15 am-11:04 pm

1 stop19h 49m

$700

PortlandLondon

PWM - LHR

PWMLHR

Portland

Tue 11/18

4:53 pm-8:45 am

1 stop10h 52m

London Heathrow

Tue 11/25

11:45 am-11:54 pm

2 stops17h 09m

$721

PortlandLondon

PWM - LHR

PWMLHR

Portland

Mon 12/1

6:00 am-6:55 am

1 stop19h 55m

London Heathrow

Tue 12/9

10:00 am-11:21 pm

2 stops18h 21m

$722

PortlandLondon

PWM - LHR

PWMLHR

Portland

Wed 12/3

4:43 pm-11:25 am

2 stops13h 42m

London Heathrow

Wed 12/10

10:00 am-11:21 pm

2 stops18h 21m

$726

PortlandLondon

PWM - LHR

PWMLHR

Portland

Fri 11/14

2:30 pm-4:00 pm

2 stops20h 30m

London Heathrow

Fri 11/21

6:40 pm-11:54 pm

2 stops34h 14m

$734

PortlandLondon

PWM - LHR

PWMLHR

Portland

Tue 11/18

1:25 pm-9:00 am

1 stop14h 35m

London Heathrow

Tue 11/25

4:10 pm-11:54 pm

1 stop12h 44m

$749

PortlandLondon

PWM - LHR

PWMLHR

Portland

Tue 11/18

12:38 pm-6:30 am

2 stops12h 52m

London Heathrow

Tue 11/25

1:10 pm-11:41 pm

2 stops15h 31m

$753

PortlandLondon

PWM - LHR

PWMLHR

Portland

Fri 11/14

5:37 pm-10:25 am

1 stop11h 48m

London Heathrow

Fri 11/21

7:50 am-6:10 pm

2 stops15h 20m

$767

PortlandLondon

PWM - LHR

PWMLHR

Portland

Fri 3/20

2:35 pm-9:20 am

2 stops14h 45m

London Heathrow

Mon 5/4

6:40 am-11:59 pm

2 stops22h 19m

$836

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 14 resultsSorted by cheapest first
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See travel insights to London from

How to get the cheapest flight ticket from Portland, Maine to London Heathrow Airport

Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip

What is the typical price of a round-trip flight between Portland, Maine and London Heathrow Airport?

What is the cheapest month to fly to London Heathrow Airport?

The month of May is, on average, the cheapest month to fly to London Heathrow Airport from Portland, Maine, with most prices found around $696. If you’re not able to fly to London Heathrow Airport in May, then April is your next best option. Flight prices from Portland, Maine to London Heathrow Airport during April average around $710.

What is the cheapest day to depart on your flight to London Heathrow Airport?

Our data shows that Tuesday is the least expensive day to fly to London Heathrow Airport. Tickets to fly out on this day can be as low as $656. The most expensive day to fly to London Heathrow Airport is Saturday, with ticket prices averaging around $717.

What is the cheapest time of day to depart on your flight to London Heathrow Airport?

According to our data, the cheapest time of day to fly to London Heathrow Airport is at noon. momondo users have found flights departing from Portland, Maine to London Heathrow Airport at noon for as low as $656. Keep in mind that these prices may fluctuate based on what airline you choose and the time of year you plan to travel. Flights in the evening are often more expensive with an average ticket price of $690.

When to book flights from Portland, Maine to London Heathrow Airport

Are you open to changing your travel dates? Check out the ideal times to fly from Portland, Maine to London Heathrow Airport according to our flight data. Find out which month and days have the cheapest flights.
Estimated round-trip price

Cheap Portland, Maine to London Heathrow Airport (PWM to LHR) flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from Portland, Maine to London Heathrow Airport

Direct flights

None
There are no direct flights from Portland, Maine to London Heathrow Airport. There are no popular flight routes from Portland, Maine to London Heathrow Airport.
Search flight deals

  • How far is Portland to London Heathrow by plane?

    The distance between Portland and London Heathrow is about 3170.3 mi. In terms of flight time, this usually takes a little over 9h 40m.

  • When did momondo last update prices for flights from Portland Airport to London Heathrow Airport?

    Prices for flights from Portland Airport to London Heathrow Airport refresh daily.

  • How many operators does momondo search for flights from Portland Airport to London Heathrow Airport?

  • How old do you have to be to fly from Portland Airport to London Heathrow Airport?

    Although the minimum age for a child to fly alone is five, airlines that offer an unaccompanied minor (UMNR) service may have their own age limits, which could be impacted by factors such as flight length, timing, and layovers. It is recommended that you verify with the airline you are booking with for travel from Portland Airport to London Heathrow Airport.

  • What documentation or ID do you need to fly to London Heathrow Airport?

    The necessary travel and health documents for your London Heathrow Airport trip may vary depending on your travel plans and individual circumstances. Generally, you should have various documents, such as a national ID card or driver's license and a passport that is valid for six months beyond your scheduled arrival date. We recommend seeking advice from your airline or a trusted third party, such as IATA.

  • What is the most popular airline from Portland, Maine to London Heathrow Airport?

Best airlines flying from Portland, Maine to London Heathrow Airport

Compare and see reviews for airlines that fly from Portland, Maine to London Heathrow Airport with momondo
Airline
Rating
Free Cancellation
Price
United AirlinesPriceFrom $648Free CancellationRating
7.4
8,933 reviews
Search United Airlines flights
DeltaPriceFrom $825Free CancellationRating
7.9
7,962 reviews
Search Delta flights

Traveling to a place near London?

Book flights to London if you plan to visit one of these locations
Gatwick
Hounslow
Milton Keynes
Luton
Dover
Slough
Guildford
Dartford
Hayes
Crawley
Chelmsford
Brentwood
Salisbury
Stansted
Folkestone
Ilford
Colchester
Romford
Swindon
Stratford-upon-Avon

Why use momondo?

Why should I use momondo to find a flight deal from Portland to London?

To find the flight that best suits your needs, momondo gathers a range of flights from a large pool of different airlines and agents; you can then use our insights and filters to find and book the right flight to London from Portland.

Can I find flights from Portland to London with flexible booking policies on momondo?

Yes. momondo enables you to select and highlight flights to London from Portland with this policy.

How can momondo help me find flights from Portland to London?

Once you have performed a search for Portland to London flights, momondo helps you find the right one by offering useful filters to narrow down your flight selection. Flights can be filtered by multiple factors such as airline, airport and price; but also by other criteria like aircraft type and payment method.

I’m not ready to book a flight from Portland to London right now. Can momondo alert me if prices change?

If you are simply researching potential flights to London, momondo offers a useful price alert feature which will track prices for flights to London from Portland and alert you when they change.

An easier way to manage your London Heathrow Airport trip

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